列算术

Question

我遇到了一些代码问题。我有三列浮点数。我想添加三列，然后除以其中一列。

谢谢

我有以下代码：

df1 = pd.read_csv(file1)
cols = ['Opening Balance', 'Subscriptions/Redemptions', 'Gain (Loss)'] 
for col in cols:
    df1[col] = pd.to_numeric(df1[col], errors='coerce')
    num = ((df1['Opening Balance'] + df1['Subscriptions/Redemptions'] + df1['Gain (Loss)']))
    denom = df1['Opening Balance']
    performance = num/denom
df['new column'] = performance

我最终得到一个新列，不过是 NaN。

我希望得到一个浮动作为回报

Answer 1

我认为您需要从 for 循环中删除 num 和 denom 部分。否则，它们每次都会被覆盖。更像是这样的：

df1 = pd.read_csv(file1)
cols = ['Opening Balance', 'Subscriptions/Redemptions', 'Gain (Loss)'] 
for col in cols:
    df1[col] = pd.to_numeric(df1[col], errors='coerce')

# escaped for loop here
# also removed parentheses
num = df1['Opening Balance'] + df1['Subscriptions/Redemptions'] + df1['Gain (Loss)']
denom = df1['Opening Balance']
performance = num/denom
df['new column'] = performance

每次您尝试将其中一列转换为数字时，它仅适用于该列。然后，当您尝试将其他“非数字”列与它相加时，您可能会得到NaN，因为它们尚未转换。完成循环中的转换，然后定义您的denom 和num。

另外，我认为您的 num 定义不需要括号